ECG-Synchronized CT Angiography in 324 Consecutive Pediatric Patients: Spectrum of Indications and Trends in Radiation Dose

Abstract

The aim of the study is to describe the spectrum of indications for pediatric ECG-synchronized CT angiography (CTA), the main determinants of radiation exposure, and trends in radiation dose over time at a single, tertiary referral center. The study was IRB approved and HIPAA compliant with informed consent waived. Between 2005 and 2013, 324 pediatric patients underwent ECG-synchronized CTA to evaluate known or suspected cardiovascular abnormalities (109 female, median age 8.1 years). The effective dose (ED) was calculated using age-specific correction factors. Univariate and multivariate regression analyses were performed to identify predictors of radiation dose. The most common primary indications for the CTA examinations included known or suspected coronary pathologies (n = 166), complex congenital heart disease (n = 73), and aortic pathologies (n = 41). Median radiation exposure decreased from 12 mSv for patients examined in the years 2005-2007 to 1.2 mSv for patients examined in the years 2011-2013 (p < 0.001). Patients scanned using a tube potential of 80 kV (n = 259) had a significantly lower median radiation dose (1.4 mSv) compared to patients who were scanned at 100 kV (n = 46, median 6.3 mSv) or 120 kV (n = 19, median 19 mSv, p < 0.001). Tube voltage, followed by tube current and the method of ECG-synchronization were the strongest independent predictors of radiation dose. Growing experience with dose-saving techniques and CTA protocols tailored to the pediatric population have led to a tenfold reduction in radiation dose over recent years and now allow routinely performing ECG-synchronized CTA in children with a radiation dose on the order of 1 mSv.

Third-generation dual-source 70-kVp chest CT angiography with advanced iterative reconstruction in young children: image quality and radiation dose reduction

“…We achieved a reasonably low effective radiation dose of 0.36 mSv and the mean CTDI vol of 0.31 mGy using a high-pitch 70-kVp mode. These values are distinctively lower than those in some studies and similar to those in other studies [20,23,24,46,47]. We found no other study that compared [43].…”

“…Nie et al [46] examined 40 children and calculated a mean effective radiation dose of 0.29 mSv for prospectively ECG-triggered CT angiography with a 128-slice dual-source CT scanner with sequential mode. Meinel et al [24] examined a cohort of 259 children with an 80-kVp prospectively ECG-triggered protocol and reported an effective dose of 0.59 mSv (range 0.07-3.5 mSv). These studies demonstrate that the selection of tube potential and tube current, and the method of ECG-synchronization are the main determinants of radiation exposure during ECG-synchronized CT angiography in children.…”

“…In addition, the high sensitivity of the pediatric population to radiation and the cumulative radiation dose in critically ill children require careful handling with this technique [21,22]. Prospectively ECG-triggered high-pitch spiral mode accounts for most effective radiation dose and allows for the examination of the whole heart within a single heartbeat [23][24][25][26]. The feasibility and accuracy of high-pitch CT imaging in children with congenital heart disease has been demonstrated by Han et al [20].…”

The utility of computed tomographic angiography in a neonate on extracorporeal membrane oxygenation with extreme cyanosis after Blalock–Taussig shunt

“…CTA is being increasingly utilized in patients with congenital heart disease,[3] and its use in neonates on ECMO before surgery has been reported. [4] Unlike DC, CTA can be performed with any type of venous access.…”

Multimodality Imaging Guidelines of Patients with Transposition of the Great Arteries: A Report from the American Society of Echocardiography Developed in Collaboration with the Society for Cardiovascular Magnetic Resonance and the Society of Cardiovascular Computed Tomography

“…170 A single-institution study showed the median dose for electrocardiographically gated studies in pediatric patients was reduced from 12 to 1.2 mSv between 2005 and 2013. 173 To minimize diagnostic risk, each scan must be tailored to the individual patient and clinical question. Radiation dose for CT angiography has been shown to be 15-fold less than cardiac catheterization in pediatric patients using newer technology and aggressive radiation dose reduction.…”